Magnetic properties and giant magnetoresistance in La0.67Ca0.33MnOx bulk material

The magnetic and transport properties of a perovskite-type crystal sample with a nominal composition La0.67Ca0.33MnOx have been investigated in the temperature range from 5 to 300 K with applied magnetic fields up to 5 T. Magnetization data obtained in the zero-field-cooled process exhibit the magnetic behavior with a Néel temperature, TN∼50 K and Curie temperature, TC∼300 K. The interesting feature in the temperature dependence of magnetoresistance is the appearance of a peak at T∼50 K, with value Δρ/ρ=[ρ(0)-ρ(5T)]/ρ(5 T)=1300% at the Néel temperature, rather than at Curie temperature.